Control device

Abstract

A control device is disclosed for an electric heating device with a PTC element as an auxiliary heater in a motor vehicle. The control device has a control housing in which a printed circuit board, equipped with at least one power switch is provided. The power switch is applied against a cooling surface in a heat-conducting manner under pretension via an elastic pretensioning element. The pretensioning element is formed from an elongated piece of a soft-elastic plastic part extruded with at least one through-opening. Also disclosed is an electric heating device having such a control device.

The invention claimed is: 
     
       1. A control device for an electric heating device having a PTC element as an auxiliary heater in a motor vehicle, the control device comprising:
 a control housing; and 
 a printed circuit board provided in the control housing, the printed circuit board being equipped with at least one power switch, wherein the power switch is applied against a cooling surface in a heat-conducting manner under a pretensioning force via an elastic pretensioning element, and wherein the pretensioning element is an elongated piece of a soft-elastic plastic part that is extruded with at least one through-hole extending in a direction substantially transverse to a transmission direction of the pretensioning force. 
 
     
     
       2. The control device according to  claim 1 , wherein the pretensioning element abuts internally against a control housing cover of the control housing, and wherein the control housing cover has a bulge circumferentially positively retaining the pretensioning element. 
     
     
       3. The control device according to  claim 2 , wherein the control housing cover is formed of a metal sheet, and wherein the bulge has a stiffening effect on the control housing cover. 
     
     
       4. The control device according to  claim 1 , wherein a plurality of through-holes are provided next to each other in a direction substantially transverse to a transmission direction of the pretensioning force. 
     
     
       5. The control device according to  claim 1 , wherein a plurality of through-holes are provided one above the other along a transmission direction of the pretensioning force. 
     
     
       6. The control device according to  claim 1 , wherein the pretensioning element forms form-fit surfaces that positively embrace the power switch and/or mating surfaces associated with the printed circuit board. 
     
     
       7. The control device according to  claim 1 , wherein the pretensioning element is provided between a plurality of power switches, and wherein a control housing cover and the plurality of power switches are held under pretension between the control housing cover and associated cooling surfaces. 
     
     
       8. The control device according to  claim 7 , wherein the pretensioning element has a plurality of pretensioning bodies, each of which is associated with one of the power switches and which are connected to one another via a connecting web extending transversely to the at least one through-hole. 
     
     
       9. The control device according to  claim 8 , wherein the connecting web forms an integral hinge. 
     
     
       10. An electric heating device comprising:
 a control housing surrounding a connection chamber; 
 a heater housing surrounding a heating chamber, wherein the control housing and the heater housing are separated from one another by a partition wall, from which at least one PTC heating assembly projects into the heater housing as a heating fin, wherein the PTC heating assembly has at least one PTC element and contact lugs which are electrically conductively connected to the PTC element for energizing the PTC element with different polarities and which are electrically connected in the control housing, wherein a heat sink is exposed in the heating chamber, which heat sink is connected in a heat-conducting manner to a cooling surface provided in the connection chamber, wherein a printed circuit board, equipped with at least one power switch, is provided in the connection chamber, the power switch is applied in a heat-conducting manner against a cooling surface under a pretensioning force via an elastic pretensioning element, and wherein the pretensioning element is an elongated piece of a soft-elastic plastic part extruded with at least one through-opening extending in a direction substantially transverse to a transmission direction of the pretensioning force. 
 
     
     
       11. The electric heating device according to  claim 10 , wherein the pretensioning element acts indirectly on the power switch with the interposition of the printed circuit board therebetween.